we currently have a bug that the last activity underneath a question includes moderated content, but the number of answers to the right not. We are working on a solution.
Sorry for the inconvenience and best regards, Sebastian
I had an issue that could have the same title, but is not the same. In my case the actual answer just disappeared with no messages. I had to go to my activity stream and come back out to see it. If the answer is being moderated before showing up as Sebastian Wolf suggests, it would be nice to have a message to that effect. I had read this thread before, otherwise I was tempted to repost while I was still on the original Question's screen.
Update: It worked fine this time!